Clive Palmer threatens to sue Rupert Murdoch

Clive Palmer has threatened to sue Rupert Murdoch and accused the media mogul's ex-wife of "spying'', less than 24 hours after filing an $800,000 defamation suit against Liberal National Party candidate Mal Brough.

Mr Palmer threatened to sue the media tycoon over the opinion piece published in The Australian on Thursday, which questions whether he is a mining magnate and billionaire.

Mr Palmer accused Mr Murdoch of telling his reporters what to write and said he needed to be brought to account.

Mr Palmer is also suing Mr Brough for more than $800,000 over the James Ashby affair.

He is seeking $355,500 in general damages and $450,000 in aggravated compensation.

Mr Palmer recently claimed Mr Brough asked him to fund a legal campaign that would destroy the reputation of his political rival Peter Slipper - the former House of Representatives speaker standing as an independent for Fisher.

Mr Brough strenuously denied the allegation, saying "there has been inconsistency on this issue from day one from Mr Palmer".

In his statement of claim, Mr Palmer said Mr Brough’s comments implied that he was a liar and lacked honesty and integrity.

Mr Ashby’s sexual harassment case against Mr Slipper was dismissed in the Federal Court in December last year, two months after Mr Slipper, a former Liberal National Party member, resigned as House of Representatives speaker following the publication of explicit text messages.

The federal court ruled Mr Ashby was working with Mr Brough to damage Mr Slipper’s reputation.

Mr Brough and Mr Ashby have denied any wrongdoing. The federal court decision is subject to appeal.